Tablets inhibit the formation or rust and scale, neutralize pH imbalance, controls electrolysis, lubricates and seals internal, external and coolant-to-oil leaks. These are the same tablets as used by many OEM auto and truck manufacturers. Designed to enhance the use of antifreeze or can also be used in water. When used in water alone, it is also recommended to use a cooling system anti-rust and water pump lube. Compatible with ALL brands of antifreeze including conventional green or blue (silicate-based) and extended life red/orange or yellow (OAT/HOAT) coolant. Stops most leaks in only a few minutes.